1. Field of Invention
This invention relates to air ducting and more particularly to a duct for channeling air from outside an enclosure of a personal computer (PC) to a processor (CPU) of the computer ensuring that the operative temperature of the processor remains below that at which operation of the processor is adversely affected.
2. Prior Art
A need for heat management of operative components of computer systems has been well known for many years. For example, a large computer system typically is installed in a space having its own air-conditioning system with special ducting connected to various pieces of system equipment. Alternately, the enclosure of a personal computer (PC) typically includes one or two fans for drawing into and then exhausting air from an enclosure of the PC. With respect to such smaller computer systems, there often is a need to supplement built-in cooling to insure that excessive heat does not impede the operation of the CPU and other system components.
One example of a supplement cooling system for computers is disclosed in U.S. Pat. No. 5,107,398. This auxiliary system includes a pair of fan units installed inside a housing of the computer. A first fan unit draws air from a bottom inlet in the housing for discharge into a plenum having nozzles that direct the air onto electronic components in the housing. A second fan unit then draws this air over power supply units of the computer. An outlet of this second fan unit connects with an inlet section of a diffuser. This inlet section is defined by outwardly and downwardly diverging sidewalls connected by a top and bottom wall. An outer end of the inlet section then connects with a downwardly turned section having a bottom end outlet. This bottom outlet end connects with a plenum chamber of an exhaust fixture carried in an opening in a sidewall of the housing. Air discharges from the exhaust fixture through a set of vertically spaced apart, V-like shaped directional vanes.
Another cooling system for a computer is set out in U.S. Pat. No. 6,021,042. This cooling system includes redundant air moving units comprising a pair of spaced apart blower units located in an air moving chamber. Each blower unit discharges air into a mixing chamber defined in part by a top and bottom wall. Each wall is formed with an inward extending air director that restricts air flowing into the mixing chamber. Air discharging from the mixing chamber flows through a pair of spaced apart outlets in a sidewall of the chamber and then into a yoke-shaped diffuser having spaced apart outlets. Air from these diffuser outlets circulates over heat sink discs of the computer microprocessor.
U.S. Pat. No. 6,064,571 shows several fan duct modules particularly adapted to facilitate a flow of air to cool electronic components of a computer. One module includes an air guiding duct having an inlet end to receive air from outside the computer and a downwardly facing outlet end that connects with an upwardly facing intake of a blower. Air from the blower then discharges downward to flow over and cool electronic components below. A second duct module is designed to fit inside a wall of a computer chasse while a third module attaches to an outer sidewall of the computer chasse.
A still further heat dissipation enhancing device is set out in U.S. Pat. No. 6,163,453 and includes a fan duct having a cuboidal-like shape. In one sidewall of the duct is a discharge opening for an electric fan that pulls air from within the duct and then exhausts this air outwardly. Air enters the duct from a top opening located proximate a microprocessor of the computer and a rear side opening located proximate to a power supply of the computer. Alternatively, the top opening in the duct may be replaced by an arcuate-shaped top wall protrusion having a rectangular, vertically positioned front opening. Initial fan discharge may be increased by the duct including an extension chamber aligned with the fan.
Computer cooling systems also may combine air cooling with liquid-base cooling. For example, U.S. Pat. No. 6,343,378 discloses a dual water-air cooling arrangement for a microprocessor of a computer. Positioned above the computer microprocessor is a heat sink having fins to receive beat transferring from the microprocessor to the heat sink. These fins release this heat to a stream of air from a fain unit located just above the fins and to coolant circulating in piping extending through the fins.
Lastly, computer cooling units may include air diffusers having spaced apart fins to channel the flow of air through diffusers, see U.S. Pat. Nos. 6,256,197 and 6,333,852.
A duct, particularly adapted for channeling air from outside of an enclosure of a personal computer (PC) to cool a processor (CPU) of the PC, has a hollow body. This body is defined by spaced apart sidewalls that are connected by an inner wall and an outer wall to form an interior passageway through the duct body. In a lower section of the outer wall of the duct body is an enlarged intake opening prepared to align with vent openings in a side panel of an enclosure of the PC. As the walls of the lower section of the duct body extend upward, the sidewalls pinch inward to form a narrow top end. This lower section narrow top end then connects with a narrow bottom end of an upper section of the duct body. The inner wall of the upper section arches inward while the outer wall of the upper section flares upward. Inner end edges of the walls of the upper section define a vertically positioned outlet opening prepared to locate next to the processor.
For use, first the side panel of the PC enclosure is removed so that the cooling duct may be placed inside the enclosure. The duct is positioned inside the enclosure so that the intake opening in the duct lower section locates adjacent to the vent openings in the reinstalled enclosure side panel and the outlet opening in the duct upper section faces an integrally formed heat sink of the processor. With the PC enclosure again reassembled and the PC is energized, the CPU intake fan draws ambient air from outside enclosure through the side panel vent openings. A portion of this air flows through the duct interior passageway to discharge directly on the heat sink of the processor to insure that the temperature of the processor remains in its optimum operative range.
The duct of this invention provides several advantages over computer air cooling ducts known or in use.
A first advantage is that a further fan unit may be installed in the upper section of the duct to enhance the volume of air discharging from the duct onto the processor heat sink. This supplemental volume of cooling air may be needed where the PC operates in a non air-conditioned environment or the configuration of vent openings is based more aesthetics than function.
A second advantage is that the duct may be made in three pieces, an inner portion, an upper cover, and a lower cover. The three-piece duct has reduced tooling costs allowing this duct to be sold at a more competitive price. Also, the pieces comprising this duct may be more compactly packaged for shipping. As required, these pieces may be readily snapped together or disassembled.
The three-piece duct is particularly adaptable, an important feature since the PC enclosure side panel vent openings-processor relationship varies depending on the particular PC. Additionally, a PC enclosure may contain sound proofing material. For example, where the transverse distance between the enclosure side panel and the computer processor is limited, just the duct inner portion need be used. In this case, side edges of sidewall parts of the duct inner portion are positioned against an inside surface of the PC enclosure side panel. Another example is where the enclosure side panel vent openings do not operatively align with the duct intake opening. In this case, the duct may be installed without a lower cover thereby enlarging the duct intake opening.
Finally, walls of the duct lower section and duct upper section may be formed with trim lines allowing severance of fragments of the duct. Upon severance of part of the duct lower section, the vertical distance between the duct intake and outlet openings is reduced. Removal of a fragmentary part of the duct upper section reduces the transverse distance between the intake and outlet openings.